Jan 11, 2013 5:30pm PST
. >> reporter: backstage in las vegas, alexis wineman, miss montana, beaming like the others as they compete for the crown. but hers is a journey unlike any other. the little girl with the big smile but hiding underneath it, a giant hurdle. >> we knew for a long time there was something wrong, we just didn't know what it was. >> reporter: the little girl unable to relate to other children at school. the unexplained tantrums. the hours spent alone. she had autism but her parents and teachers didn't know it. one teacher saying, i don't get paid enough to handle this. no one talked about it in her small montana town. she wasn't diagnosed until she was 11 and no one thought she would ever make it here. at 18, alexis defied the odds. the first contestant with autism to compete in miss america. so you've had a little practice? >> oh, yes. >> reporter: and for the talent portion she plans a stand-up act. this is where you have to be funny up there. >> yes. i'm always funny up there. >> reporter: the same little girl who will tell you she never got the jokes. how did you know you were funny?